There are diseases that prevent a patient from maintaining normal control of the flow of fluids and/or other bodily matter in a lumen of a bodily organ. (The term “patient” generally includes human beings, but may also include animals.) For example, a patient suffering from urinary incontinence, which is a common disease that is very embarrassing to a patient, typically occurs where the patient has lost full control of urine flow in the urethra because of a malfunctioning of the urethral sphincter. Anal incontinence often occurs because of a malfunctioning of the anal sphincter, which causes an uncontrolled drainage of fecal matter through the anus. Impotence is typically due to an inability to sufficiently reduce blood flow from the penis so that an erection can be achieved. Reflux disease is typically due to a malfunctioning of the cardia, which causes stomach acids to be regurgitated into the esophagus when the stomach wall moves during digestion.
One prior solution to the problem of malfunctioning sphincters has been to implant an artificial sphincter that replaces a malfunctioning sphincter. A variety of artificial sphincters have been used in the past. These artificial sphincters have included cuffs, clamping elements or inflatable bands that are applied externally around the bodily organ that is connected to the malfunctioning sphincter.
For example, U.S. Pat. No. 3,750,194 discloses a hydraulic cuff applied around the urethra of a patient suffering from urinary incontinence Hydraulic fluid flowing to the hydraulic cuff causes the cuff to squeeze the urethra and restrict fluid flow through it.
U.S. Pat. No. 6,074,341 discloses a mechanical device in the form of a loop member that is applied around a bodily organ to replace the organ's missing or damaged sphincter. The loop member includes a wire which is used to constrict the organ in question to close the lumen therein.
A disadvantage common to all prior artificial sphincters is that hard fibrosis may form around the artificial sphincter over time and may cause malfunction of the artificial sphincter. Thus, the formed fibrosis may sooner or later become a hard fibrotic layer which may make it difficult for the artificial sphincter to work.
Another more serious disadvantage is that the element that constricts, clamps or restricts a bodily organ may injure the tissue wall of the organ. Thus, a consequence of the element's constricting action on the organ is that the element might erode into the organ over time, and in a worst case, penetrate the constricted wall portion of the organ. In addition, blood circulation in the constricted tissue wall portion of the organ is eventually hampered by the pressure exerted by the element, so that poor blood circulation, or worse, no blood circulation results in deterioration of the constricted tissue.
One solution to prevent tissue deterioration due to poor blood circulation could be to apply two or more separately operating constricting elements along respective tissue wall portions of the organ and operate the elements sequentially, whereby each tissue wall portion would have time to recover, i.e., restore normal blood circulation while one of the other tissue wall portions is constricted. However, an apparatus devised in accordance with this solution would have several disadvantages. First, the apparatus would require a large amount of space, making it impractical to implant. Second, the operation of the apparatus in moving the constricting elements between constricting and non-constricting positions day and night would require a large power supply. Such a large power supply would necessitate the implantation of a very large, high capacity battery and/or a sophisticated system for continuous wireless transmission of energy from outside the patient's body for frequent charging of an implanted rechargeable battery. Thus, because of its large size and high power consumption, the apparatus would be impractical or even unrealistic. Third, a sophisticated control system would be necessary to control the moving elements. Finally, such a complicated apparatus of the type described above would significantly add to the costs of treating a malfunctioning sphincter.
Another solution to the problem of malfunctioning sphincters that has been previously used has been the electric stimulation of the sphincter, to restore its normal function, i.e., the contraction and closing of its associated lumen. This solution would work where the normal sphincteric function is somewhat reduced and has not completely ceased. European patent application 1004330 A1 discloses an example of such a solution, in which electric pulses are delivered to the lower esophageal sphincter of a patient suffering from reflux disease to minimize reflux. However, the esophageal sphincter has to be continuously stimulated with electric pulses to keep it closed, except when the patient eats, which may result in a decreased stimulation effect over time. An even more serious drawback to this solution is that the continuous stimulation over time might cause tissue deterioration due to poor blood circulation.
The use of electric stimula to restore the sphincteric function of a malfunctioning sphincter is only possible if the sphincter responds sufficiently to the stimula, i.e., closes the lumen in question. In cases where the sphincteric function of a sphincter has completely ceased, or the sphincter has been removed from the patient's body, electric stimulation cannot be employed.
Electric stimulation of bodily organs other than sphincters can only insignificantly affect the flow in the organ in question. For example, where the organ is the small intestine of an anal incontinent patient, electric stimulation of the small intestine affects fecal flow, but could not possibly fully close the fecal passageway, at least not by employing the necessary low stimulation intensities that are harmless to the human body.